On snapshot builds there is only one revision I'm interested in knowing: the revision the build started with. But on a release build, I'm interested in two revisions: the one I started with, and the revision that gets tagged in Mercurial. It isn't that this information can't be looked up; that's easy. But I can't count how many times I've needed to explain to developers why there is a discrepancy between the revision recorded by Jenkins and the revision tagged in HG. It'd be nice to have both on the build page to keep developers from thinking I've released the wrong code.